Electrostatic Chuck Assembly for Plasma Processing Apparatus

ABSTRACT

An electrostatic chuck including a workpiece support surface, clamping layer, heating layer, thermal control system, and sealing band is disclosed. The sealing band surrounds an outer perimeter of the electrostatic chuck including at least a portion of the workpiece surface. The sealing band has a width greater than about 3 millimeters (mm) up to about 10 mm. Plasma processing apparatuses and systems incorporating the electrostatic chuck are also provided.

PRIORITY CLAIM

The present application claims the benefit of priority of U.S.Provisional Patent Application Ser. No. 63/131,440, titled “MultizoneElectrostatic Chuck for Processing Apparatus,” filed on Dec. 29, 2020,which is incorporated herein by reference. The present applicationclaims the benefit of priority of U.S. Provisional Patent ApplicationSer. No. 63/131,448, titled “Multipolar Electrostatic Chuck,” filed onDec. 29, 2020, which is incorporated herein by reference. The presentapplication claims the benefit of priority of U.S. Provisional PatentApplication Ser. No. 63/194,256, titled “Electrostatic Chuck Assemblyfor Plasma Processing Apparatus,” filed on May 28, 2021, which isincorporated herein by reference. The present application claims thebenefit of priority of U.S. Provisional Patent Application Ser. No.63/194,529, titled “Electrostatic Chuck Assembly for Plasma ProcessingApparatus,” filed on May 28, 2021, which is incorporated herein byreference.

FIELD

The present disclosure relates generally to a plasma processingapparatus for plasma processing of a workpiece. More specifically, thepresent disclosure is directed to an electrostatic chuck assembly forthe plasma processing apparatus.

BACKGROUND

Various types of process chambers are available for processing differenttypes of workpieces. The workpieces may comprise, for instance, glassplates, films, ribbons, solar panels, mirrors, liquid crystal displays,semiconductor wafers, and the like. Many different types of processchambers are available, for instance, for processing semiconductorwafers during the manufacture of integrated circuit chips. The processchambers may be used to anneal the wafers, carry out chemical vapordeposition, physical vapor deposition, plasma and chemical etchingprocesses, thermal processes, surface engineering and other processes.These types of process chambers typically contain a workpiece supportfor holding the workpiece within the chamber.

In many processes, it is desirable to control certain parameters of theworkpiece during processing in order to control uniformity duringprocessing. Although various attempts have been made to design workpiecesupports that can control temperature non-uniformities, variousdeficiencies and drawbacks remain. Accordingly, improved workpiecesupports and plasma processing apparatuses and systems are needed.

BRIEF DESCRIPTION OF THE DRAWINGS

Detailed discussion of embodiments directed to one of ordinary skill inthe art are set forth in the specification, which makes reference to theappended figures, in which:

FIG. 1 depicts an example processing apparatus according to exampleembodiments of the present disclosure.

FIG. 2 depicts an example workpiece support according to exampleembodiments of the present disclosure.

FIG. 3 depicts an example workpiece support according to exampleembodiments of the present disclosure.

FIG. 4 depicts a top down view of a clamping layer having two clampingelectrodes according to example embodiments of the present disclosure.

FIG. 5 depicts a top down view of a heating layer having one or moreheating electrodes according to example embodiments of the presentdisclosure.

FIG. 6 depicts a bottom view of a clamping layer and a trace connectionaccording to example embodiments of the present disclosure.

FIG. 7 depicts a bottom view of a clamping layer and a trace connectionaccording to example embodiments of the present disclosure.

FIG. 8 depicts a bottom view of a clamping layer and a trace connectionaccording to example embodiments of the present disclosure.

FIG. 9 depicts a top down view of a thermal control system according toexample embodiments of the present disclosure.

FIG. 10 depicts a portion of a workpiece support according to exampleembodiments of the present disclosure.

FIG. 11 depicts a top-down view of a clamping layer having a pluralityof clamping electrodes according to example embodiments of the presentdisclosure.

FIG. 12 depicts a top-down view of a clamping layer having a pluralityof clamping electrodes according to example embodiments of the presentdisclosure.

FIG. 13 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 14 depicts a schematic of electrical connections according toexample embodiments of the present disclosure.

FIG. 15 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 16 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 17 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 18 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 19 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 20 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 21 depicts a schematic of electrical connections and a plurality ofclamping electrodes according to example embodiments of the presentdisclosure.

FIG. 22 depicts an example workpiece support according to exampleembodiments of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments, one or moreexamples of which are illustrated in the drawings. Each example isprovided by way of explanation of the embodiments, not limitation of thepresent disclosure. In fact, it will be apparent to those skilled in theart that various modifications and variations can be made to theembodiments without departing from the scope or spirit of the presentdisclosure. For instance, features illustrated or described as part ofone embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that aspects of the presentdisclosure cover such modifications and variations.

Aspects of the present disclosure are discussed with reference to a“workpiece” “wafer” or semiconductor wafer for purposes of illustrationand discussion. Those of ordinary skill in the art, using thedisclosures provided herein, will understand that the example aspects ofthe present disclosure can be used in association with any semiconductorworkpiece or other suitable workpiece. In addition, the use of the term“about” in conjunction with a numerical value is intended to refer towithin ten percent (10%) of the stated numerical value. A “pedestal”refers to any structure that can be used to support a workpiece. A“remote plasma” refers to a plasma generated remotely from a workpiece,such as in a plasma chamber separated from a workpiece by a separationgrid. A “direct plasma” refers to a plasma that is directly exposed to aworkpiece, such as a plasma generated in a processing chamber having apedestal operable to support the workpiece.

As used herein, use of the term “about” in conjunction with a statednumerical value can include a range of values within 10% of the statednumerical value.

Some plasma processing apparatuses include a workpiece support that caninclude an electrostatic chuck. Generally, an electrostatic chuckincludes one or more electrodes embedded in a ceramic puck. When theelectrode is charged with electricity, differences in the electrostaticcharges in the electrode and the workpiece will hold the workpiece onthe workpiece support. Existing electrostatic chucks include monopolar(e.g., a single electrode) or dipolar (e.g., to electrodes) designs.However, the present inventors have discovered that electrostatic forcesgenerated by the electrodes can create process non-uniformities on theworkpiece. For example, existing bipolar electrostatic chucks can causeside-to-side etch rate non-uniformity patterns due to the layout of theelectrodes, which have a clear side-to-side pattern in electric fielddistribution due to the connections of the electrodes to theirrespective power source or sources.

Accordingly, example aspects of the present disclosure provide for aunique radial layout for the chucking (e.g., clamping) electrodes. Thechucking electrodes can be thermally isolated and electrically connectedin a manner resulting in a total of four isolated zones in the chuckingelectrodes. In general, example aspects of the present disclosure aredirected to an electrostatic chuck that includes a clamping layer havingone or more clamping electrodes. The clamping electrodes include a firstclamping electrode defining a first clamping zone and a second clampingzone. The clamping electrodes include a second clamping electrodedefining a third clamping zone and a fourth clamping zone. The firstclamping zone and the second clamping zone are separated by a first gap.The first clamping zone and second clamping zone are electricallyconnected by at least one electrical connection extending across thefirst gap. The third clamping zone and the fourth clamping zone areseparated by a second gap. The third clamping zone and fourth clampingzone are electrically connected by at least one electrical connectionextending across the second gap.

The first and second clamping electrodes are disposed in a radial mannersuch that the first clamping zone is radially most inward, the secondclamping zone is radially inward from the third clamping zone andradially outward from the first clamping zone, and the third clampingzone is radially inward from the fourth clamping zone and radiallyoutward from the second clamping zone. The clamping zones can correspondto the placement of one or more heating zones defined in a heating layerwith heating electrodes.

Further, the electrostatic chuck can include a thermal control system.The thermal control system can include a layer disposed in the chuck inorder to distribute a thermal exchange fluid or gas (e.g., helium). Thethermal control system can include one or more flow channels that areinterconnected to one or more release apertures disposed in certainrelease zones. For example, in embodiments, the release zones ofapertures can be disposed in a radial pattern corresponding to theclamping zones and/or heating zones. For example, the first zone ofrelease apertures can be located radially most inward and the secondzone of release apertures can be located radially outward from the firstzone of release apertures. The third zone of release apertures can belocated radially outward from the second zone of release apertures andradially inward from the fourth zone of release apertures.

In certain implementations, the electrostatic chuck can also include asealing band. The sealing band generally sits atop at least a portion ofthe workpiece support surface of the electrostatic chuck, morespecifically the sealing band surround an outer perimeter of theelectrostatic chuck. The sealing band is configured to have a width W1that is greater than about 3 millimeters (mm) up tot about 10 mm. Sizingthe sealing band according to example aspects of the present disclosure,provides a more robust sealing band that is better able to withstandprocessing and cleaning conditions without being damaged such thatleakage of heat exchange gas likely to occur.

The electrostatic chuck according to example embodiments of the presentdisclosure can provide numerous benefits and technical effects. Forinstance, at least two clamping electrodes can be radially arranged andconnected resulting in at least four thermally isolated zones. Eachthermally isolated zone can be controlled in order to improve processuniformity. Additionally, electrostatic chuck bias compensation (e.g.,chucking voltage offset) can be used to actively control the etch rateuniformity and/or chemical deposition on workpieces during processing.Furthermore, disposing certain heating zones and/or zones of releaseapertures as provided can further enhance temperature control in theradial and azimuthal directions across the workpiece. Further, sizingthe sealing band as provided herein, ensures that the sealing band ismore durable and is less susceptible to erosion from plasma exposureand, therefore, less likely to leak heat exchange gas around theperimeter of the workpiece.

In addition, some plasma processing apparatuses include a workpiecesupport that can include an electrostatic chuck. Generally, anelectrostatic chuck includes one or more electrodes embedded in aceramic puck. When the electrode is charged with electricity,differences in the electrostatic charges in the electrode and theworkpiece will hold the workpiece on the workpiece support. Existingelectrostatic chucks include monopolar (e.g., a single electrode) ordipolar (e.g., two electrodes) designs. However, the present inventorshave discovered that electrostatic forces generated by the electrodescan create process non-uniformities on the workpiece. For example,existing bipolar electrostatic chucks can cause side-to-side etch ratenon-uniformity patterns due to the layout of the electrodes, which havea clear side-to-side pattern in electric field distribution due to theconnections of the electrodes to their respective power source orsources. Many prior solutions for improving workpiece uniformity incertain plasma processing systems having electrostatic chucks focused onRF electrodes or antennas in order to generate a more uniform plasmadensity and/or more uniform ion energy. Other solutions focused onimproved electrostatic chuck heating designs in order to provide moreuniform temperature control across the wafer.

Accordingly, example aspects of the present disclosure provide for aunique electrostatic chuck assembly that includes a pixelated array of aplurality of micro-electrodes each coupled to at least one RF biassource and a clamping power source. The clamping power source isconfigured to provide clamping power to each of the plurality ofmicro-electrodes so that each of the plurality of micro-electrodes isconfigured to act as a clamping electrode for the workpiece. Further, acontroller is provided that is configured to control the RF bias sourceto independently adjust one or more RF parameters of RF bias power toone of the plurality of micro-electrodes relative to at least one otherof the plurality of micro-electrodes. Accordingly, each of theelectrodes can be operated independently from each other in a variety ofmanners in order to adjust workpiece uniformity. Indeed, going frommonopolar or bipolar electrode configurates to a pixelated array of aplurality of micro-electrodes as provided herein can result in aneffective electrostatic chuck having clamping electrodes capable ofproviding necessary chucking (e.g., clamping) ability and multipurposeuniformity tuning capabilities.

The electrostatic chuck according to example embodiments of the presentdisclosure can provide numerous benefits and technical effects. Forinstance, each of the plurality of micro-electrodes in the pixelatedarray can be independently controlled allowing for more precise controlof selected individual surface areas of the electrostatic chuck, whichcan aid in workpiece uniformity. For example, use of a plurality ofmicro-electrodes can allow an operator to modify selected sections ofthe electrostatic chuck, as needed, in order to adjust RF parameters,clamping functionality, and/or workpiece uniformity.

Referring to FIGS. 1-2, for instance, one embodiment of a workpieceprocessing system 100 made in accordance with the present disclosure isshown. In the embodiment illustrated in FIG. 1, the system includes aprocess chamber 9. The process chamber 9 includes a workpiece processingstation 13. The processing station 13 includes a workpiece support 12made in accordance with the present disclosure. The process chambershown in FIG. 1 includes one processing station 13 for processing oneworkpiece, such as a semiconductor wafer. It should be understood,however, that the process chamber 9 may include more than one processingstation in other embodiments. As shown, the processing station 13includes a processing region 14. The processing region 14 is incommunication with an isolation valve 17. Isolation valve 17 opens andcloses so as to allow the workpiece to be exchanged. The isolation valve17 seals to the process chamber wall 10.

In the embodiment illustrated, the workpiece support 12, or at least aportion of the workpiece support, includes an electrostatic chuck 24.Electrostatic chucks 24 are configured to produce an electrostatic forcethat holds a workpiece 16 onto the top surface of the workpiece support12. More particularly, the electrostatic chucks function by applyingone, monopolar, or two, bipolar, high DC voltages between anelectrostatic chuck and the workpiece. For instance, two, bipolar DCvoltages cause both positive and negative charges on one side of thefirst dielectric layer 28. These charges, generate attractive Coulombforces between the top surface of the workpiece support 12 and aworkpiece 16. As will be described in greater detail below, theworkpiece support 12 includes a clamping layer having one or moreclamping electrodes that enables the electrostatic chuck function. Itshould be understood, however, that the teachings and principles of thepresent disclosure are also applicable to other workpiece supports thatdo not necessarily comprise electrostatic chucks.

The processing station 13 is configured to receive a workpiece 16 on theworkpiece support 12. Once the workpiece 16, such as a semiconductorwafer, is loaded into the process chamber, the workpiece 16 is subjectedto an energy source in order for the workpiece 16 to undergo a desirablephysical and/or chemical change. Energy sources that may be used toprocess workpieces can include, for instance, an ion source, a reactivechemical source, a thermal source, a plasma source, or mixtures thereof.Thermal sources that may be used to subject the workpieces to energyinclude light energy sources, such as, plasma arc lamps, tungstenhalogen lamps, microwave, inductive, resistive heaters, or mixturesthereof.

In certain embodiments, process chamber 10 includes a plasma source forsubjecting a workpiece to a plasma. The plasma is supplied by means ofone or more induction coils 39 that are in communication with a RFimpedance matching device (not shown) and in communication with a RFpower supply (not shown). While only one induction coil 39 is shown, thedisclosure is not so limited. Indeed any number of induction coils couldbe provided in order to generate a plasma in the process chamber 9.

The workpiece processing system 100 of FIG. 1 is provided for purposesof illustration and discussion. Those of ordinary skill in the art,using the disclosures provided herein, will understand that theelectrostatic chuck(s) according to example aspects of the presentdisclosure can be used in any suitable processing system (e.g., anysuitable plasma processing system).

Referring now to FIG. 2, as shown, the workpiece support 12 includes aworkpiece-receiving surface 18 that is defined by a dielectric portion20. The dielectric portion 20 is positioned on top of a base that, inthis embodiment, includes a first base portion 22 positioned over asecond base portion 15. In embodiments, the combination of dielectricportion 20, first base portion 22, and second base portion 15 can bereferred to as the electrostatic chuck 24. The electrostatic chuck 24,and representative layers, is made from any suitable metallic or ceramicmaterial. For instance, in one embodiment, the base portions 22 and 15can be made from aluminum. The electrostatic chuck 24 can also includealumina, aluminum nitride, yttria, zirconia, and/or any other chemicallyresistant ceramic or plastic material. The electrostatic chuck 24 isattached to a workpiece support pedestal 57. The purpose of the pedestal57 is to provide rigid mechanical support for the electrostatic chuck 24and to provide both thermal and electrical isolation from the processchamber 9.

As described above, the dielectric portion 20 is positioned on top ofthe first base portion 22 and defines the workpiece-receiving surface18. The dielectric portion 20 can be made from any suitable dielectricmaterial, such as a ceramic material. The dielectric portion cancomprise multiple layers of a dielectric material or can comprise asingle layer. In the embodiment the dielectric portion 20 includes afirst dielectric layer 28 positioned on top of a second and thickersecond dielectric layer 30. The first dielectric layer 28, for instance,can have a thickness of about 0.4 to about 1 mm, while the seconddielectric layer 30 can have a thickness of from about 2 mm to about 5mm.

As shown in FIG. 2, the workpiece support 12 can further be incommunication with an RF conduit 36 that is in communication with an RFimpedance matching device (not shown) in communication with an RF powersupply 38 for supplying an RF bias power to the workpiece.

In an alternative embodiment, the RF source power can be coupled to theworkpiece support 12 through an RF impedance matching device (not shown)that is in communication with a RF conduit 36. In this embodiment, thereis no additional RF power supplied to the processing station 13. In analternative embodiment, no RF source power is coupled to the workpiecesupport 12. During workpiece processing, the RF power source can beenergized to produce ions and electrons in the plasma for desiredchemical reactions with a top surface of the workpiece 16. In otherembodiments, the RF power source provides independent control of theenergy that ions have when they strike the top surface of the workpiece.The RF power supply and the DC power supply can both be grounded usingany suitable technique. In one embodiment, for instance, both RF and DCpower supplies may be grounded to an electrode in communication with theprocessing chamber. In the embodiments illustrated, the process chamberemploys inductive-coupled RF power to generate and maintain a plasmanecessary for workpiece processing. The RF bias power is capacitivelycoupled to the plasma through the workpiece support 12.

In order to load and unload workpieces on the workpiece-receivingsurface 18, the workpiece support 12 can include any suitable mountingdevice. For instance, in one embodiment, the workpiece support 12 mayinclude a plurality of lift pins (not shown) that can be used toproperly position a workpiece 16 on the workpiece-receiving surface 18and to elevate and lower the workpiece 16 on the workpiece-receivingsurface. In this regard, the workpiece support 12 can include aplurality of pin channels for a lift pin assembly. In one embodiment,for instance, the workpiece support 12 may include three pin channelsfor accommodating three pins.

In embodiments, the workpiece processing system 100 can include acontroller 175. The controller 175 controls various components inprocessing chamber 9 to direct processing of workpiece 16. For example,controller 175 can be used to control power sources (e.g., DC powersource, AC power source, and/or RF power source) connected to theelectrodes in the clamping layer 40 and/or heating layer 50.Additionally and/or alternatively, controller 175 can be used to controlthe thermal management system 70 in order to control or maintain adesired workpiece temperatures. The controller 175 can also implementone or more process parameters, such as controlling the gas flowcontrollers and/or altering conditions of the processing chamber 9during processing of the workpiece 16. The controller 175 can include,for instance, one or more processors and/or one or more memory devices.The one or more memory devices can store computer-readable instructionsthat, when executed by the one or more processors, cause the one or moreprocessors to perform operations, such as any of the control operationsdescribed herein.

Referring now to FIG. 3, the electrostatic chuck 24 portion of theworkpiece support 12 is shown. As shown, a workpiece 16 is placed on theworkpiece-receiving surface 18. A sealing band 80 is disposed around aperimeter of the electrostatic chuck 24 and is disposed on at least aportion of the workpiece-receiving surface 18. The sealing band 80 willbe further discussed herein. A clamping layer 40 is disposed between thefirst dielectric layer 28 and the second dielectric layer 30. Theclamping layer 40 can include one or more clamping zones 42, 44, 46, 48,which will be discussed further herein. A heating layer 50 is disposedunderneath of the clamping layer 40 in the z-direction. The heatinglayer 52 can be disposed within the second dielectric layer 30 orbetween the second dielectric layer 30 and the first base portion 22.The heating layer includes one or more heating zones 52, 54, 56, 58,which will be discussed further herein. A thermal control system 70 isdisposed in the electrostatic chuck 24. The thermal control system 70can be disposed within the second dielectric layer 30 or the first baseportion 22. The Similar to the clamping layer 40 and the heating layer50, the thermal control system 70 includes one or more zones 72, 74, 76,78 of release apertures 73 for releasing a heat exchange fluid or gas inorder to control the temperature of the workpiece 16. The thermalcontrol system 70 will be discussed further herein.

As shown in FIGS. 3 and 4, in one embodiment in order to form theelectrostatic chuck 24, a clamping layer 40, including one or moreclamping electrodes, can be positioned within the electrostatic chuck24. For example, in embodiments, the clamping layer 40 can be positionedbetween the first dielectric layer 28 and the second dielectric layer30. The one or more clamping electrodes present in the clamping layer 40can be placed in communication with a DC power supply 34 as shown inFIG. 2. Two different DC voltages can be supplied by a single DC powersupply or by two independent power supplies. The DC power supply 34supplies the voltages necessary to create an electric field forproducing electrostatic attraction between the workpiece-receivingsurface 18 and a workpiece 16 held on the surface. The amount of voltagecreated by the DC power supply can be used to adjust the amount ofelectrostatic attraction. Further, when it is necessary to remove theworkpiece 16 from the workpiece support 12, the DC power supply can beturned off so that no voltage is being produced or can create a reversepolarity voltage from the starting potential. DC voltages typically varyfrom about 500 to 2000 volts.

As shown in FIG. 4, the clamping layer 40 can include one or moreelectrodes, such as at least two electrodes 41,43, disposed in radialarrangement. The first clamping electrode 41 can be coupled to anegative charge source, while the second clamping electrode 43 can becoupled to a positive charge source. In other embodiments, however, itis contemplated that either the first or second clamping electrode 41,43could be coupled to either a positive or a negative charge source. Forexample, in embodiments, the first clamping electrode 41 is coupled to anegative DC voltage and the second clamping electrode 43 is coupled to apositive DC voltage. Furthermore, the first clamping electrode 41 andthe second clamping electrode 43 can be coupled to a DC power source, ACpower source, and/or a RF power source. In embodiments, both the firstclamping electrode 41 and the second clamping electrode 43 can becoupled to the same RF power source.

Furthermore, as shown in FIG. 4, the clamping layer 40 includes a firstclamping electrode 41 and a second clamping electrode 43 disposed inradial arrangement. That is, the first clamping electrode 41 is disposedradially inward from the second clamping electrode 43. The firstclamping electrode 41 defines a first clamping zone 48 and a secondclamping zone 46. The second clamping electrode 43 defines a thirdclamping zone 44 and a fourth clamping zone 42. As shown, the firstclamping zone 48 is disposed radially most inward. The second clampingzone 46 is disposed radially outward from the first clamping zone 48 andradially inward from the third clamping zone 44. The fourth clampingzone 42 is disposed radially most outward.

Each of the clamping zones 42, 44, 46, and 48 can be thermally isolatedfrom one another. For example, the first clamping zone 48 and the secondclamping zone 46 can be separated by a gap 45 a. The third clamping zone44 and the fourth clamping zone 42 can also be separated by a gap 45 b.Furthermore, gap 45 a reduces thermal conduction between the firstclamping zone 48 and the second clamping zone 46 and the second gap 45 breduces thermal conduction between the third clamping zone 44 and thefourth clamping zone 42. The gaps 45 a,45 b can include an air gap orcan comprise any suitable material. For example, in certain embodiments,the gaps 45 a,45 b comprise a dielectric material (e.g., ceramicmaterial).

One or more electrical connections 47 can be used to couple firstclamping zone 48 with the second clamping zone 46. For example, aplurality of electrical connections 47 can be used, such as at leastfive electrical connections 47. Similarly, one or more electricalconnections 49 can be used to couple the third clamping zone 44 to thefourth clamping zone 42. The number of electrical connections 49 caninclude more than 1, such as more than 5, such as more than 10. Incertain embodiments, the number of electrical connections 47 connectingthe first and second clamping zones 48,46 can be less than the number ofelectrical connections 49 connecting the third and fourth clamping zones44, 42.

While each of the two clamping electrodes 41 and 43 are thermallyisolated into two zones each, they are connected via the electricalconnection 47 or 49 in order to keep them at approximately the sameelectrical potential. For example, in embodiments, the first clampingzone 48 and second clamping zone 46 carry the same chucking voltage forthe positive pole, while the third clamping zone 44 and fourth clampingzone 42 carry the same chucking voltage for the negative pole.Generally, the offset between the positive chucking voltage and thenegative chucking voltage can either target balancing the clampingforces in order to compensate for a self-DC bias on the workpiece or canbe purposely operated in an unbalanced mode for uniformity tuningpurposes. For example, a workpiece can be processed and the uniformityof the workpiece can be assessed. Upon assessment if uniformity is atissue, the electrostatic chuck bias can be adjusted in order to adjustworkpiece uniformity for workpieces processed in the future. Forexample, the clamping voltage of either the first clamping electrode 41or the second clamping electrode 43 can be adjusted in order to adjustworkpiece uniformity.

Furthermore, as noted, the clamping electrodes 41 and 43 can beconnected to any suitable power source or voltage source (e.g., a DCpower source or an RF power source). In certain embodiments, theclamping electrodes 41,43 are coupled to a voltage source (e.g., a highDC voltage source) the voltage source is configured to provide a DCoffset ad adjustment to balance one or more clamping forces or to adjustworkpiece processing uniformity. In certain configurations, the clampingelectrodes are coupled to a bipolar high voltage supply (e.g., a bipolarhigh DC voltage supply). In certain configurations, each of the clampingzones 42, 44, 46, and/or 48 can be operated independently from eachother in order to adjust workpiece uniformity. For instance, inembodiments, a different amount of power output and/or a different powersource itself can be applied to any of the clamping zones 42, 44, 46,and 48 in order to adjust workpiece uniformity. For example, a differentamount of DC voltage, RF power output, and/or a different power sourcecan be applied to any of the clamping zones 42, 44, 46, 48 in order toadjust workpiece uniformity. For example, in certain embodiments,application of different amounts of DC voltage and/or RF power appliedacross the clamping zones 42, 44, 46, 48 can modify the clampingelectrodes 41,43 so as to provide a tri-polar or quadra-polarelectrostatic chuck. Furthermore, the clamping electrodes can beconnected to a DC power source or an RF power source with one or morecapacitors disposed along the RF path in order to prevent DC voltagefrom interfering with or accessing the RF delivery. Additionally oralternatively, an inductor and/or resistor in series can be disposed inthe DC path to prevent RF voltage from accessing the DC voltage supply.

Additionally, one or more traces can be utilized in order to arrange theclamping zones 42, 44, 46, 48 in any type of electrical configuration.For example, the first clamping zone 48 and the third clamping zone 44,could be electrically coupled to one or more traces embedded in a layerof the electrostatic chuck 24 to form the first clamping electrode 41and the second clamping zone 46 and the fourth clamping zone 42 could beelectrically coupled to one or more traces embedded in a layer of theelectrostatic chuck 24 to form the second clamping electrode 43.Moreover, in embodiments, the first clamping zone 48 and the fourthclamping zone 42 could be electrically coupled to one or more tracesembedded in a layer of the electrostatic chuck 24 to form the firstclamping electrode 41 and the second clamping zone 46 and third clampingzone 44 could be electrically coupled to one or more traces embedded ina layer of the electrostatic chuck 24 to form the second clampingelectrode 43. In such embodiments, the traces used to connect differentclamping zones 42, 44, 46, 48 can be located generally in a layer of theelectrostatic chuck that is underneath of the clamping layer 40. Oncethe selected clamping zones are coupled via a trace, the trace can thenbe connected to any suitable power source as described herein.

In one or more embodiments, a heating layer 50 can be disposed in theworkpiece support 12. For example, FIG. 5 illustrates different zones ofthe heating layer 50. For example, the heating layer 50 can include oneor more electrodes 51, such as a plurality of electrodes 51 a, 51 b, 51c, 51 d arranged in a radial pattern. For example, in certainembodiments, the heating layer 50 includes at least four electrodes 51a, 51 b, 51 c, 51 d. Each of the electrodes 51 a, 51 b, 51 c, 51 d canbe connected to a suitable AC or DC power source. In certainembodiments, the plurality of heating electrodes 51 a, 51 b, 51 c, 51 dare disposed in a radial manner to form a first heating zone 58, asecond heating zone 56, a third heating zone 54, and a fourth heatingzone 52 as shown in FIG. 5. The heating zones 52, 54, 56, and 58 can bedisposed in any manner on or within the heating layer 50 in theelectrostatic chuck 24.

In certain embodiments, the heating zones 52, 54, 56, and 58 correspondto the clamping zones 42, 44, 46, and 48 present in the clamping layer40. For example, as shown in FIG. 3, the first heating zone 52 isdisposed under the first clamping zone 42 in the z-direction. The secondheating zone 56 is disposed under the second clamping zone 46 in thez-direction. The third heating zone 54 is disposed under the thirdclamping zone 44 in the z-direction. The fourth heating zone 52 isdisposed under the fourth clamping zone 42 in the z-direction.Additionally, the widths of the heating zones 52, 54, 56, 58 aresubstantially the same as the widths of the clamping zones 42, 44, 46,48. For example, the width of the first heating zone 58 is substantiallythe same as the width of the first clamping zone 48. The width of thesecond heating zone 56 is substantially the same as the width of thesecond clamping zone 46. The width of the third heating zone 54 issubstantially the same as the width of the third clamping zone 44. Thewidth of the fourth heating zone 52 is substantially the same as thewidth of the fourth clamping zone 42. Disposition of the heating zones52, 54, 56, 58 in relation to the clamping zones 42, 44, 46, 48 can helpwith thermal isolation from zone to zone radially. Furthermore, eachheating zone 52, 54, 56, 58 overlaps with its corresponding clampingzone 42, 44, 46, 48 to help with thermal transition from zone to zoneradially.

Each of the heating zones 52, 54, 56, 58 can be independently controlledin order to adjust heating across different radial regions of theworkpiece during processing. For example, each heating zone 52, 54, 56,58 can be formed from at least one electrode, each individual electrode(e.g., 51 a, 51 b, 51 c, 51 d) used to form the separate heating zones52, 54, 56, 58 can be independently connected to a power source.Accordingly, different amounts and/or types of power can be supplied toeach electrode in order to adjust the temperature for each of theheating zones 52, 54, 56, 58.

In order to connect each of the electrodes (e.g., clamping electrodesand/or heating electrodes) present in the electrostatic chuck to theappropriate or desired power source, one or more traces and/or vias canbe used to connect the electrodes to the power sources. Referring toFIGS. 6-8, for example, in certain embodiments a trace 60 is used toconnect the second clamping electrode 43 to a suitable power source. Forinstance, the trace 60 can run from the second electrode 43 towards thecenter of the clamping layer 40. In certain embodiments, the trace 60 isrun in a layer located underneath of the clamping electrodes 41, 43towards a centrally-located delivery socket location(s) in order tocouple the second clamping electrode 43 to a suitable power source.Furthermore, in embodiments, one or more vias 61 can be used to connectthe trace 60 to the second electrode 43 and to the delivery socketlocation. Vias 61 can be used in order to run the trace 60 in a layerunderneath of the clamping layer 40, that is the trace 60 is not locatedin the same plane orthogonal to the z-direction as the clamping layer40. Similarly, one or more traces 60 can be run from each of the heatingelectrodes (e.g., 51 a, 51 b, 51 c, 51 d) towards centrally-locateddelivery socket locations in order to couple the heating electrodes to asuitable power source. Similar to the clamping electrode arrangement,one or more vias can be used in order to run the traces 60 underneath ofthe heating layer 50, that is the trace 60 (or traces) used to connectthe heating electrodes to the power source(s) is not located in the sameplane orthogonal to the z-direction as the heating layer 50.

In certain embodiments, the workpiece support 12 can further include athermal control system 70. The thermal control system 70 can include oneor more channels 71 for circulating a thermal exchange fluid or athermal exchange gas (e.g., helium). The thermal control system 70 canbe included as a layer disposed within the electrostatic chuck. Forexample, in certain embodiments the thermal control system 70 layer canbe located underneath of the workpiece 16 when the workpiece is disposedon the workpiece support 12. For example, in certain embodiments thethermal control system 70 can be disposed between the workpiece 16 andthe clamping layer 40. In certain other embodiments, however, it iscontemplated that the thermal control system 70 could be located betweenthe clamping layer 40 and the heating layer 50 or underneath of theheating layer 50. The thermal control system 70 can be disposed withinthe electrostatic chuck in any manner suitable for processing ofworkpieces 16 in the processing chamber. Referring back to FIG. 3, thethermal control system 70 is disposed underneath of both the clampinglayer 40 and the heating layer 50 in the z-direction.

As shown in FIG. 9, the thermal control system 70 includes one or morechannels 71 and also includes one or more release apertures 73. The oneor more channels 71 are interconnected via a pattern to each of therelease apertures 73. The release apertures 73 are organized accordingto zones 72, 74, 76, 78 of release apertures 73. A single thermalexchange fluid or thermal exchange gas inlet 75 is shown. For example,in embodiments, the thermal control system 70 includes a first zone 78of release apertures 73, a second zone 76 of release apertures 73, athird zone 74 of release apertures 73, and a fourth zone 72 of releaseapertures 73. The first zone 78 of release apertures 73 is disposedradially most inward. The second zone 76 of release apertures 73 isdisposed radially outward from the first zone 78 of release apertures 73and radially inward from the third zone 74 of release apertures 73. Thethird zone 74 of release apertures 73 is disposed radially inward fromthe fourth zone 72 of release apertures 73 and radially outward from thesecond zone 76 of release apertures 73. While at least four zones (e.g.,72, 74, 76, 78) of release apertures 73 are shown, the disclosure is notso limited. Indeed, any number of zones of release apertures could beconfigured into the thermal control system 70 disclosed herein. Further,the first zone 78 of release apertures 73 includes the fewest number ofrelease apertures 73 as compared to the other zones 72, 74, 76. Thesecond zone 76 of release apertures 73 includes more release apertures73 than the first zone 78 of release apertures 73 but fewer releaseapertures 73 as compared to the third zone 74 of release apertures 73.The third zone 74 of release apertures 73 includes more releaseapertures 73 than the second zone 76 of release apertures 73 but fewerrelease apertures 73 as compared to the fourth zone 72 of releaseapertures 73. The fourth zone 72 of release apertures 73 includes themost release apertures 73 as compared to the other zones 74, 76, 78.

In embodiments, each of the zones 72, 74, 76, 78 of release apertures 73generally correspond to the one or more heating zones 52, 54, 56, 58and/or clamping zones 42, 44, 46, 48, respectively. Namely, the zones72, 74, 76, 78 of release apertures 73 can be disposed underneath or ontop of the corresponding zones of the clamping layer 40 and the heatinglayer 50. Such disposition is illustrated in FIG. 3. In certainembodiments, the zones 72, 74, 76, 78 of release apertures can bedisposed in a layer located underneath of both the clamping layer 40 andthe heating layer 50. Accordingly, one or more heat exchange conduitscan be drilled through the workpiece-receiving surface 18, the clampinglayer 40, and the heating layer 50, so that the thermal exchange fluidor gas released from the release apertures 73 located in each of thezones 72, 74, 76, 78 can come into contact with a backside of theworkpiece 16 in order to adjust the temperature of the workpiece 16. Inother embodiments, however, the thermal control system 70 can be locateddirectly underneath of the workpiece 16 when it is held on the workpiecesupport 12. For instance, the zones 72, 74, 76, 78 of release apertures73 can be located within or just below the first dielectric layer 28. Inembodiments, one or more conduits can be drilled through the only thefirst dielectric layer 28 so that the heat exchange gas or heat exchangefluid released from the release apertures 73 located in each of thezones 72, 74, 76, 78 can come into contact with a backside of theworkpiece 16 in order to adjust the temperature of the workpiece 16.

Referring now to FIG. 10, in certain embodiments, (e.g., those includinga thermal control system capable of helium distribution), theelectrostatic chuck 24 can include a sealing band 80. The sealing band80 generally surrounds an outer perimeter of the electrostatic chuck 24including at least a portion of the workpiece-receiving surface 18. Thesealing band 80 is configured to have a width W1 that is greater thanabout 3 millimeters (mm) up to about 10 mm, such as greater than 4 mm upto about 9 mm, such as greater than 5 mm up to about 8 mm, such asgreater than 5 mm, up to about 7 mm. The sealing band 80 generally sitsatop the electrostatic chuck 24 in order to seal any thermal exchangefluid and/or gas (e.g., helium) underneath the workpiece 16 when theworkpiece 16 is chucked on to the electrostatic chuck 24. Further,electrostatic chucks often go through in-situ dry-cleaning (ISD) and canfurther go through off-situ cleaning during maintenance. If the sealingband is damaged or worn after hours of use or during cleaning, suchdamage can cause leakage of thermal exchange gas (e.g., helium) suchthat the workpiece temperature is not maintained as it should be.Further, if thermal exchange gas (e.g., helium) is able to seep out andaround the sealing band such that it has access to the top of theworkpiece during process, this can cause further uniformity issuesduring workpiece processing. Accordingly, the width W1 of the sealingband 80 provided herein is such that the sealing band 80 is more robustand is better able to withstand processing and cleaning conditionswithout being damaged such that leakage of thermal exchange gas is notlikely to occur.

FIG. 11 illustrates a top-down view of a plurality of clampingelectrodes 200. As shown in the embodiments illustrated in FIG. 11, atleast four clamping electrodes 202, 204, 206, 208, are provided.Furthermore, while FIG. 11 illustrates an embodiment including fourclamping electrodes 200, the disclosure is not so limited. Indeed, anynumber of clamping electrodes 200 can be included according to desiredprocessing parameters. While the clamping electrodes can be disposed inany pattern, as shown, they are disposed in a concentrically radialpattern. In embodiments, the plurality of clamping electrodes 200 can beformed into a clamping layer 212 as part of the dielectric portion 20 ofthe electrostatic chuck 24. The first clamping electrode 202 is theinnermost disposed electrode with the second clamping electrode 204disposed radially outward from the first clamping electrode 202 andradially inward from the third clamping electrode 206. The thirdclamping electrode 206 is disposed radially outward from the secondclamping electrode 204 and radially inward from the fourth clampingelectrode 208. The fourth clamping electrode 208 is disposed radiallymost outward. As noted, each of the clamping electrodes 202, 204, 206,208 are coupled to one or more power sources that can be individuallyconfigured, as will be further described hereinbelow.

FIGS. 12-13 illustrate top-down views of a pixelated array of aplurality of micro-electrodes 210. As shown, the plurality ofmicro-electrodes 210 are disposed in a pattern arrangement generallyabout a clamping layer 212 that can be incorporated into theelectrostatic chuck assembly. For example, the pixelated array ofmicro-electrodes 210 can be arranged in any pattern such as square orrectangular patterns. For example, the micro-electrodes 210 can bedisposed in a square grid pattern having the same number of columns androws. In other embodiments, the micro-electrodes 210 can be arranged ina rectangular pattern. The micro-electrodes 210 can also be arranged ina variety of circular patterns, including radially extending circularpatterns, having rows of concentric circles of micro-electrodes 210disposed to form the pixelated array. The micro-electrodes 210,themselves, can include any suitable shape including circular (as shownin FIG. 12), ovular, triangular, rectangular, square (as shown in FIG.13), and/or any combination thereof. The micro-electrodes 210 can alsoinclude strips or plates arranged in any configuration or pattern. Insome embodiments, the micro-electrodes 210 can be randomly dispersedacross the clamping layer 212 and/or be formed from a plurality ofshapes distributed across the clamping layer 212. In certainembodiments, the micro-electrodes 210 can include pixelatedmicro-electrodes. Each micro-electrode 210 can be microns in size. Forexample, the diameter of each micro-electrode 210 can be in the range ofmicrons. Furthermore, while any number of micro-electrodes 210 can beused, in certain embodiments the electrostatic chuck 24 and/ordielectric portion 20 includes from about 2 micro-electrodes up to about200 micro-electrodes, such as from about 20 to about 180micro-electrodes, such as from about 40 to about 160 micro-electrodes,such as from about 60 to about 140 micro-electrodes, such as from about80 to about 120 micro-electrodes.

As noted above, each of micro-electrodes 210 can be coupled to one ormore power sources. For example, in certain embodiments each of themicro-electrodes 210 (illustrated in FIGS. 12-13) can each be connectedto different power sources. Suitable power sources can include anysuitable DC power source, AC power source, and/or RF power source. Incertain embodiments, the DC power source includes a DC power sourcecapable of producing a high voltage DC current. For example, in certainembodiments each of the micro-electrodes 210 are electrically coupled toat least one RF bias source and at least one clamping power source(e.g., a DC power source). In certain embodiments, the RF bias sourceand the clamping power source can be the same or different. Further, theclamping power source can include any suitable DC power source, AC powersource, and/or RF power source. The clamping power source is configuredto provide clamping power to each of the plurality of micro-electrodes210 so that each of the plurality of micro-electrodes is configured toact as a clamping electrode for the workpiece 16. Additionally and/oralternatively, in embodiments, each of the plurality of micro-electrodes210 can be coupled to an RF bias source. In certain embodiments, the RFbias source includes a plurality of RF bias sources, each one of the RFbias sources is coupled to at least one of the plurality ofmicro-electrodes 210. The controller 175 can be configured to controlthe RF bias source(s) in order to independently adjust RF parameters ofRF bias power to each of the plurality of micro-electrodes 210. Forexample, in certain embodiments, the RF parameters can include one ormore of RF power, RF frequency, or RF phase.

FIG. 14 depicts one embodiment in which the electrical connections 300of seven micro-electrodes 210 are diagrammed (diagram also shown in FIG.15). As depicted, each of the seven micro-electrodes 210 can beconnected to a power source (e.g., a high voltage DC power supply or aRF bias source) via one or more electrical connections 300. Although notshown, each of the other micro-electrodes 210 provided in the pixelatedarray can also be connected to a suitable power source via one or moreelectrical connections. A DC power source is illustrated in FIG. 14, butthe power source could be an RF source as indicated above. The array ofmicro-electrodes 210 can be connected in either monopolar operation(e.g., the same polarity for all of the micro-electrodes) or in bipolaroperation (e.g., with negative polarity for some selectedmicro-electrodes and positive polarity for the rest of themicro-electrodes). The bipolar configuration can be localized and/orglobal.

In some embodiments, each of a plurality of clamping electrodes 210 canbe switched according to a pulse-width modulation control scheme. Forinstance, FIG. 16 depicts a diagram of a plurality of micro-electrodes210 being switched together at an individually-configured frequencyf_(individual), where all the depicted electrodes 210 are provided witha fixed voltage (e.g., which can be the same or different). For example,each clamping electrode 210 is configured to an electrical connection300 having an electrical switching element 302 associated therewith.Each micro-electrode 210 and connected electrical connection 300 areeach coupled to individual power sources 304. Although a DC power sourceis illustrated in FIG. 16, the power sources 304 can include anysuitable DC power source, AC power source, and/or RF power source.

FIG. 17 depicts a diagram of a plurality of micro-electrodes beingswitched together each at an individually-configured frequencyf_(individual), where all the depicted micro-electrodes 210 are providedwith an adjustable voltage (e.g., which can be adjusted to be the sameor different). As shown in FIG. 17, all of the switching elements 302can be turned on and off at the same frequency although theindividually-configured frequency f_(individual) for eachmicro-electrode 210 can be different from each other to further enableion energy distribution uniformity. In yet further embodiments, inaddition to the adjustable voltage sources, each switching element 302,can be switched at an individually-configured frequency f_(individual),as shown in FIG. 18. In embodiments, the electrical switching elements302 can include SiC MOSFETs with high breakdown voltage ratings that canbe configured to be controlled with signals at their gates. Othersuitable switches can be used without deviating from the scope of thepresent disclosure.

In some embodiments, the individually-configured switching elements 302can be tied to a common power source 306, as shown in FIGS. 19-20. Forexample, common power source 306 can include any suitable DC powersource, AC power source, and/or RF power source. For example, each ofthe RF bias source and/or clamping power sources for the individualmicro-electrode 210 can be offset from a main voltage that is providedby a main power source (e.g., from the common power source 306) for therespective desired source. For example, each of the micro-electrodes 210can share one common power source with adjustments available to eachindividual micro-electrode 210. For example, in certain embodiments eachof the plurality of micro-electrodes 210 can be coupled to one main DCpower source with individual clamping voltages supplied to each of theindividual micro-electrodes 210 by multiple off-set DC supplies inseries with the main DC power source. The off-set DC supplies can have alower max voltage range than that of the main DC power source. Inembodiments, the clamping power source (e.g., a DC power source) isconfigured to provide a plurality of different DC voltages to each ofthe micro-electrodes 210. In other embodiments, each of the plurality ofmicro-electrodes 210 can be coupled to one main RF power source (e.g.,RF bias source) with individual RF bias voltages suppled to each of theindividual micro-electrodes 210 by multiple off-set RF supplies inseries with the main RF power source.

In certain embodiments, the common power source 306 includes a DC powersource that can be switched at a very high duty cycle with a mainfrequency f_(main) that is 10 to 1000 times higher than theindividually-configured frequency f_(individual). For yet furthercontrol, in addition to independently adjusting theindividually-configured frequency f_(individual) for each switchingelement 302, the main power source 306 can be switched and/or operatedat a main frequency f_(main), as shown in FIG. 20. In such embodiments,the main frequency f_(main) is higher than each of theindividually-configured frequencies f_(individual) for each of theplurality of micro-electrodes 210. For instance, in embodiments, theplurality of micro-electrodes 200 are powered by a DC power sourceconfigured to be switched on and off at a main frequency f_(main) thatis higher than an individually-configured frequency f_(individual) foreach of the plurality of micro-electrodes 200. For example, in certainembodiments, the controller 175 can be used to operate switchingelements 302 using a pulse width modulation to adjust a voltage appliedto at least one micro-electrode 210 coupled to the respective switchingelement 302. For example, in certain embodiments the common power source306 can include a clamping power source (e.g., a DC power source) thatis configured to provide a plurality of different DC voltages to each ofthe plurality of micro-electrodes 210. The controller 175 can beconfigured to control each of the switching elements 302 using pulsewidth modulation to adjust a voltage applied to each of themicro-electrodes 210 coupled to their respective switching elements 302.

Furthermore, the micro-electrodes 210 described with respect to FIG. 20,can also be configured to perform RF biasing with respect to theworkpiece with RF frequency. For instance, in certain embodiments, thecommon power source 306 can include an RF bias source configured toapply RF bias to at least one of the micro-electrodes 210 by controllingthe switching element 302 using pulse width modulation at a frequency ina range of about 1 kHz to 2 MHz. In embodiments, the RF bias source caninclude the clamping power source, where the clamping power sourceincludes a DC power source coupled to at least one of themicro-electrodes 210 via a switching element 302. The controller 175 canbe configured to apply RF bias to the at least one of themicro-electrodes 210 by controlling the switching element 302 usingpulse width modulation. The controller 175 can be configured to apply RFbias to at least one of the micro-electrodes 210 by controlling theswitching element 302 using pulse width modulation at a frequency in arange of about 1 kHz to about 2 MHz. Accordingly, in such embodiments, aDC power source can be configured to provide RF bias to each of theindividual micro-electrodes 210 as desired. Furthermore, in embodimentswhere the common power source 306 includes a single DC power sourcecoupled to each of the micro-electrodes 210 via the switching network(as shown in FIGS. 19-20), the controller 175 can be further configuredto selectively control one or more switching elements 302 in theswitching network to selectively apply clamping power and/or RF bias toone or more of the plurality of micro-electrodes 210.

Further, certain areas or portions of the micro-electrodes 210 can besuperimposed with RF power at a main frequency f_(main) on top of thebias RF power delivered at a bias frequency f_(bias) from the RF powersource to a baseplate and/or separate RF electrode embedded in theelectrostatic chuck 24. The bias frequency f_(bias) can be higher ascompared to the main frequency f_(main). For example, bias frequencyf_(bias) can be in the range of from about 400 kHz to about 13.56 MHz.Further, the main frequency f_(main) should be low enough in the kHzrange so that the DC power source being switched at the main frequencyf_(main) can be delivered to the micro-electrodes 210 with impedancematch.

Yet further control can be obtained as shown in FIG. 21, which combinesthe control schemes of the diagrams shown in FIGS. 18 and 20.Additionally, in certain embodiments additional reactive components canbe included in series with the micro-electrodes to form seriesresonance. Furthermore, in certain embodiments, snubber circuitry couldbe added to such embodiments to suppress oscillations.

In certain of the disclosed embodiments, the main frequency f_(main) canbe in the range of from about 1 kHz to about 2 MHz and theindividually-configured frequencies f_(individual) for each of theelectrodes can be in the range of from about 1 Hz to about 1 kHz.

FIG. 22 depicts one embodiment in which the micro-electrodes 210 areindividually powered, with the micro-electrodes 210 being fed from powersources superimposed onto the bias RF input from the main pedestal RFbias source (e.g., the micro-electrodes are DC isolated from thepedestal by the dielectric portion ceramic puck). In variousembodiments, any of the wiring schemes shown in FIGS. 14-21 can beincorporated into the assembly of FIG. 22 and referenced to the biasvoltage applied to the pedestal. In this manner, each of the controlschemes shown in FIGS. 14-21 can control voltage(s) superimposed on thebias voltage, which can be modulated at a bias frequency f_(bias), asdiscussed above.

Still referring to embodiments depicted in FIG. 22, in certainembodiments, each of the micro-electrodes 210 include pixelatedmicro-clamping electrodes that have small capacitance and can beembedded into the ceramic puck 26 or can be disposed on top of theceramic puck 26. For example, the plurality of clamping electrodes 200can be disposed on the top surface of the dielectric portion 20 and canextend from the top surface of the dielectric surface 20. In suchembodiments, an optional dielectric layer 27 (e.g., a thin ceramiclayer) can be disposed between the plurality of micro-electrodes 210 andthe workpiece. DC current or voltage can be supplied to each of themicro-electrodes 210 via a suitable DC power source. In certainembodiments, the DC current applied to each of the micro-electrodes 210is very small, such as in the scale of micro-amperes or even lowerdepending on the materials of the dielectric layer 20 and/or otherleakages associated along the delivery path (e.g., the electricalconnections 300) from the DC power source 34 to the micro-electrodes210. When the DC source 34 (e.g., a high voltage DC supply) is switchedon and off at a relatively low frequency and/or proper duty cycle in thesub-kHz range (as shown in FIG. 14), the voltage on the micro-electrodes210 responds uniformly to a square, switching waveform with very shorttransient in order to maintain clamping functionality of themicro-electrodes 210. Further, in such embodiments, the electricalconnections 300 should be as short as possible in order to minimizestrays in the DC delivery path along the electrical connections 300while still having sufficient RF impedances to block the main RF powerfrom both bias and plasma sources with small inductors and largecapacitors to form parallel resonances of the main RF frequencies ofbias and source. In such embodiments, the micro-electrodes 210 may belocated on a top surface of the dielectric portion 20. Themicro-electrodes 210 can be embedded in the dielectric portion or arephysically located above the dielectric portion 20 with the DC powersource isolated by the dielectric portion 20 from the baseplate of theelectrostatic chuck 24 that carries the bias RF power. Accordingly, eachof the micro-electrodes 210 can be configured to act as finely-tunedbias RF electrodes having their power superimposed on top of the mainbias RF power, as shown in FIG. 14. The voltage levels supplied to themicro-electrodes 210 can be varied in order to enable localizeduniformity tuning capability.

As noted, in some embodiments, the electrical connections 300 within theassembly can be kept short to reduce any stray capacitances (and/orother losses) in the DC delivery path while having sufficient RFimpedances to block the main RF power from the bias and/or plasmasources with inductors and/or capacitors to form parallel resonances forthe main RF frequencies of the bias and/or plasma source.

One example embodiment of the present disclosure is directed to anelectrostatic chuck. The electrostatic chuck can include a workpiecesupport surface configured to support a workpiece during processing. Theelectrostatic chuck can include one or more clamping electrodes defininga clamping layer. The electrostatic chuck can include one or moreheating electrodes defining a heating layer. The electrostatic chuck caninclude a thermal control system. The electrostatic chuck can include asealing band surrounding an outer perimeter of the electrostatic chuckincluding at least a portion of the workpiece support surface, thesealing band having a width greater than about 3 millimeters (mm) up toabout 10 mm.

In some embodiments, the clamping electrodes are connected to a DC powersource, AC power source, and/or an RF power source.

In some embodiments, the one or more clamping electrodes comprise afirst clamping electrode and a second clamping electrode.

In some embodiments, the first clamping electrode is coupled to anegative DC voltage, and the second clamping electrode is coupled to apositive DC voltage.

In some embodiments, the thermal control system comprises one or moreflow channels for circulating a thermal exchange fluid or a thermalexchange gas.

In some embodiments, the thermal exchange gas comprises helium gas.

In some embodiments, the flow channels are interconnected to a firstzone of release apertures, a second zone of release apertures, a thirdzone of release apertures, and a fourth zone of release apertures.

In some embodiments, the first zone of release apertures is locatedinnermost radially, wherein the second zone of release apertures islocated radially outward from the first zone of release apertures,wherein the third zone of release apertures is located radially outwardfrom the second zone of release apertures and radially inward from thefourth zone of release apertures.

In some embodiments, the second zone of release apertures includes moreapertures than the first zone of release apertures, wherein the thirdzone of release apertures includes more apertures than the second zoneof release apertures, wherein the fourth zone of release aperturesincludes more release apertures than the third zone of releaseapertures.

In some embodiments, the sealing band is configured to seal theworkpiece support surface, such that thermal exchange gas is not capableof leaking around an edge of the workpiece.

In some embodiments, the electrostatic chuck defines a first outerboundary and the clamping layer defines a second outer boundary, whereina first distance D1 between the first outer boundary and the secondouter boundary is greater than a second distance D2 defined between oneor more turns of the first electrode and/or second electrode in theclamping layer, wherein D1 is greater than about 2 millimeters (mm).

Another example embodiment of the present disclosure is directed to aworkpiece processing apparatus. The apparatus includes a processingchamber. The apparatus includes a workpiece support disposed in theprocessing chamber having a workpiece support surface configured tosupport a workpiece during processing of the workpiece, the workpiecesupport including an electrostatic chuck. The electrostatic chuck caninclude one or more clamping electrodes defining a clamping layer; oneor more heating electrodes defining a heating layer; a thermal controlsystem; and a sealing band surrounding an outer perimeter of theelectrostatic chuck, the sealing band having a width of at least about 3mm up to about 10 mm.

In some embodiments, the one or more clamping electrodes comprise afirst clamping electrode and a second clamping electrode.

In some embodiments, the thermal control system including one or moreflow channels for circulating a thermal exchange fluid or a thermalexchange gas.

In some embodiments, the thermal exchange gas comprises helium gas.

In some embodiments, the flow channels are interconnected to a firstzone of release apertures, a second zone of release apertures, a thirdzone of release apertures, and a fourth zone of release apertures.

In some embodiments, the first zone of release apertures is locatedinnermost radially, wherein the second zone of release apertures islocated radially outward from the first zone of release apertures,wherein the third zone of release apertures is located radially outwardfrom the second zone of release apertures and radially inward from thefourth zone of release apertures.

In some embodiments, the second zone of release apertures includes moreapertures than the first zone of release apertures, wherein the thirdzone of release apertures includes more apertures than the second zoneof release apertures, wherein the fourth zone of release aperturesincludes more release apertures than the third zone of releaseapertures.

In some embodiments, the sealing band is configured to seal theworkpiece support surface, such that thermal exchange gas is not capableof leaking around an edge of the workpiece.

Another example embodiment of the present disclosure is directed to asystem for processing workpiece. The system includes a processingchamber, the processing chamber configured to perform at least onetreatment process on a workpiece. The system includes a workpiecesupport disposed in the processing chamber. The workpiece supportincludes one or more clamping electrodes defining a clamping layer, oneor more heating electrodes defining a heating layer, a thermal controlsystem including one or more flow channels for circulating a thermalexchange fluid or a thermal exchange gas, wherein the flow channels areinterconnected to a first zone of release apertures, a second zone ofrelease apertures, a third zone of release apertures, and a fourth zoneof release apertures, and a sealing band surrounding an outer perimeterof the electrostatic chuck, the sealing band having a width of at leastabout 3 mm to about 10 mm. The system includes a controller, thecontroller configured to adjust one or more of (i), (ii), or (iii) inorder to adjust workpiece uniformity: (i) a power output from one ormore power sources to the one or more clamping electrodes and/or the oneor more heating electrodes; (ii) a power source to the one or moreclamping electrodes and/or the one or more heating electrodes; or (iii)a flow rate of the thermal exchange fluid or the thermal exchange gas inthe thermal control system.

Another example embodiment of the present disclosure is directed to anelectrostatic chuck. The electrostatic chuck includes a workpiecesupport surface configured to support a workpiece during processing. Theelectrostatic chuck includes a pixelated array of a plurality ofmicro-electrodes. The electrostatic chuck includes at least one RF biassource coupled to each of the plurality of micro-electrode. Theelectrostatic chuck includes a clamping power source configured toprovide clamping power to each of the plurality of micro-electrodes sothat each of the plurality of micro-electrodes is configured to act as aclamping electrode for the workpiece. The electrostatic chuck includes acontroller configured to control the at least one RF bias source toindependently adjust one or more RF parameters of RF bias power to oneof the plurality of micro-electrodes relative to at least one other ofthe plurality of micro-electrodes.

In some embodiments, the RF bias source comprises a plurality of RF biassources, each of the plurality of RF bias sources coupled to at leastone of the plurality of micro-electrodes.

In some embodiments, the one or more RF parameters comprise one or moreof RF power, RF frequency, or RF phase.

In some embodiments, the system further includes a baseplate disposedbeneath the plurality of micro-electrodes in the electrostatic chuck.

In some embodiments, the RF bias source is configured to provide RF biaspower to the baseplate.

In some embodiments, the clamping power source is configured to providea plurality of different DC voltages to each of the plurality ofmicro-electrodes.

In some embodiments, the clamping power source comprises a DC powersource, the DC power source coupled to at least one of themicro-electrodes via a switching element.

In some embodiments, the controller is configured to control theswitching element using a pulse width modulation to adjust a voltageapplied to the at least one micro-electrode coupled to the switchingelement.

In some embodiments, the RF bias source comprises the clamping powersource, the clamping power source comprising a DC power source coupledto at least one of the micro-electrodes via a switching element, thecontroller configured to apply RF bias to at least one of themicro-electrodes by controlling the switching element using pulse widthmodulation.

In some embodiments, the controller is configured to apply RF bias to atleast one of the micro-electrodes by controlling the switching elementusing pulse width modulation at a frequency in a range of about 1 kHz to2 MHz.

In some embodiments, the clamping power source comprising a single DCpower source coupled to each of the plurality of micro-electrodes via aswitching network, the controller configured to selectively control oneor more switching in the switching network to selectively apply clampingpower and/or RF bias to one or more of the plurality ofmicro-electrodes.

In some embodiments, each of the plurality of micro-electrodes areembedded in a ceramic puck.

In some embodiments, the electrostatic chuck comprises a dielectriclayer disposed between the plurality of micro-electrodes and theworkpiece.

Another example embodiment of the present disclosure is directed to aworkpiece processing apparatus. The apparatus includes a processingchamber. The apparatus includes a workpiece support comprising anelectrostatic chuck including a workpiece support surface disposed inthe processing chamber. The electrostatic chuck includes a pixelatedarray of a plurality of micro-electrodes; at least one RF bias sourcecoupled to each of the plurality of micro-electrodes; a clamping powersource configured to provide clamping power to each of the plurality ofmicro-electrodes so that each of the plurality of micro-electrodes isconfigured to act as a clamping electrode for the workpiece; and acontroller configured to control the at least one RF bias source toindependently adjust one or more RF parameters of RF bias power to oneof the plurality of micro-electrodes relative to at least one other ofthe plurality of micro-electrodes.

In some embodiments, the RF bias source comprises a plurality of RF biassources, each of the plurality of RF bias sources coupled to at leastone of the plurality of micro-electrodes.

In some embodiments, the one or more RF parameters comprise one or moreof RF power, RF frequency, or RF phase.

In some embodiments, the apparatus further comprises a baseplatedisposed beneath the plurality of micro-electrodes in the electrostaticchuck.

In some embodiments, the RF bias source is configured to provide RF biaspower to the baseplate.

In some embodiments, the clamping power source is configured to providea plurality of different DC voltages to each of the plurality ofmicro-electrodes.

In some embodiments, the clamping power source comprises a DC powersource, the DC power source coupled to at least one of themicro-electrodes via a switching element.

In some embodiments, the controller is configured to control theswitching element using pulse width modulation to adjust a voltageapplied to the at least one micro-electrode coupled to the switchingelement.

In some embodiments, the RF bias source comprises the clamping powersource, the clamping power source comprising a DC power source coupledto at least one of the micro-electrodes via a switching element, thecontroller configured to apply RF bias to at least one of themicro-electrodes by controlling the switching element using pulse widthmodulation.

In some embodiments, the controller is configured to apply RF bias to atleast one of the micro-electrodes by controlling the switching elementusing pulse width modulation at a frequency in a range of about 1 kHz to2 MHz.

In some embodiments, the clamping power source comprising a single DCpower source coupled to each of the plurality of micro-electrodes via aswitching network, the controller configured to selectively control oneor more switching in the switching network to selectively apply clampingpower and/or RF bias to one or more of the plurality ofmicro-electrodes.

In some embodiments, each of the plurality of micro-electrodes areembedded in a ceramic puck.

In some embodiments, the electrostatic chuck includes a dielectric layerdisposed between the plurality of micro-electrodes and the workpiece.

While the present subject matter has been described in detail withrespect to specific example embodiments thereof, it will be appreciatedthat those skilled in the art, upon attaining an understanding of theforegoing may readily produce alterations to, variations of, andequivalents to such embodiments. Accordingly, the scope of the presentdisclosure is by way of example rather than by way of limitation, andthe subject disclosure does not preclude inclusion of suchmodifications, variations and/or additions to the present subject matteras would be readily apparent to one of ordinary skill in the art.

What is claimed is:
 1. An electrostatic chuck, comprising: a workpiecesupport surface configured to support a workpiece during processing; oneor more clamping electrodes defining a clamping layer; one or moreheating electrodes defining a heating layer; a thermal control system;and a sealing band surrounding an outer perimeter of the electrostaticchuck including at least a portion of the workpiece support surface, thesealing band having a width greater than about 3 millimeters (mm) up toabout 10 mm.
 2. The electrostatic chuck of claim 1, wherein the clampingelectrodes are connected to one or more of a DC power source, AC powersource, or an RF power source.
 3. The electrostatic chuck of claim 1,wherein the one or more clamping electrodes comprise a first clampingelectrode and a second clamping electrode.
 4. The electrostatic chuck ofclaim 3, wherein the first clamping electrode is coupled to a negativeDC voltage, and the second clamping electrode is coupled to a positiveDC voltage.
 5. The electrostatic chuck of claim 1, wherein the thermalcontrol system comprises one or more flow channels for circulating athermal exchange fluid or a thermal exchange gas.
 6. The electrostaticchuck of claim 5, wherein the thermal exchange gas comprises helium gas.7. The electrostatic chuck of claim 5, wherein the flow channels areinterconnected to a first zone of release apertures, a second zone ofrelease apertures, a third zone of release apertures, and a fourth zoneof release apertures.
 8. The electrostatic chuck of claim 7, wherein thefirst zone of release apertures is located innermost radially, whereinthe second zone of release apertures is located radially outward fromthe first zone of release apertures, wherein the third zone of releaseapertures is located radially outward from the second zone of releaseapertures and radially inward from the fourth zone of release apertures.9. The electrostatic chuck of claim 7, wherein the second zone ofrelease apertures includes more apertures than the first zone of releaseapertures, wherein the third zone of release apertures includes moreapertures than the second zone of release apertures, wherein the fourthzone of release apertures includes more release apertures than the thirdzone of release apertures.
 10. The electrostatic chuck of claim 5,wherein the sealing band is configured to seal the workpiece supportsurface, such that thermal exchange gas is not capable of leaking aroundan edge of the workpiece.
 11. The electrostatic chuck of claim 1,wherein the electrostatic chuck defines a first outer boundary and theclamping layer defines a second outer boundary, wherein a first distanceD1 between the first outer boundary and the second outer boundary isgreater than a second distance D2 defined between one or more turns ofthe first electrode or the second electrode in the clamping layer,wherein D1 is greater than about 2 millimeters (mm).
 12. Anelectrostatic chuck, comprising: a workpiece support surface configuredto support a workpiece during processing; a pixelated array of aplurality of micro-electrodes; at least one RF bias source coupled toeach of the plurality of micro-electrodes; a clamping power sourceconfigured to provide clamping power to each of the plurality ofmicro-electrodes so that each of the plurality of micro-electrodes isconfigured to act as a clamping electrode for the workpiece; and acontroller configured to control the at least one RF bias source toindependently adjust one or more RF parameters of RF bias power to oneof the plurality of micro-electrodes relative to at least one other ofthe plurality of micro-electrodes.
 13. The electrostatic chuck of claim12, wherein the RF bias source comprises a plurality of RF bias sources,each of the plurality of RF bias sources coupled to at least one of theplurality of micro-electrodes.
 14. The electrostatic chuck of claim 12,wherein the one or more RF parameters comprise one or more of RF power,RF frequency, or RF phase.
 15. The electrostatic chuck of claim 12,further comprising a baseplate disposed beneath the plurality ofmicro-electrodes in the electrostatic chuck.
 16. The electrostatic chuckof claim 15, wherein the RF bias source is configured to provide RF biaspower to the baseplate.
 17. The electrostatic chuck of claim 12, whereinthe clamping power source is configured to provide a plurality ofdifferent DC voltages to each of the plurality of micro-electrodes. 18.The electrostatic chuck of claim 12, wherein the clamping power sourcecomprises a DC power source, the DC power source coupled to at least oneof the micro-electrodes via a switching element.
 19. The electrostaticchuck of claim 18, wherein the controller is configured to control theswitching element using a pulse width modulation to adjust a voltageapplied to the at least one micro-electrode coupled to the switchingelement.
 20. The electrostatic chuck of claim 12, wherein the RF biassource comprises the clamping power source, the clamping power sourcecomprising a DC power source coupled to at least one of themicro-electrodes via a switching element, the controller configured toapply RF bias to at least one of the micro-electrodes by controlling theswitching element using pulse width modulation.